Chief Minister Paul Henderson says he's confident the Federal Government will repeal legislation which paves the way for a nuclear waste dump in the Northern Territory.

But environmentalists and Aborigines remain sceptical Labor will make good its election promise after almost 12 months in power and no action.

A Senate committee is holding hearings for two days this week in Alice Springs on the future of the Commonwealth Radioactive Waste Management Act.

The controversial law was passed by the Howard Government in 2006 amid challenges from the NT Government, indigenous owners and green groups.

Three defence sites in the NT were being considered by the Liberals, including Harts Range and Mt Everard near Alice Springs and Fishers Ridge near Katherine.

Muckaty Station, about 120km north of Tennant Creek, was nominated by the Northern Land Council (NLC) and is regarded as the most likely site for selection.

Speaking in Darwin on Monday, Mr Henderson said he had every confidence his federal colleagues would live up to their promise to repeal the Act.

"That was an election commitment from the Prime Minister and I expect them to honour that commitment," he told reporters.

"They are just going through a process with the Senate inquiry and certainly my position hasn't changed.

"It's absolutely the science that should determine where the nuclear waste dump should go, not political opportunities."

The Rudd Government has said it will let scientific testing determine the location of the dump, which will store waste produced by the Lucas Heights nuclear reactor in Sydney.

The waste will be returned to Australia from Scotland and France from 2011.

Two months ago the Greens introduced a bill into the Senate which would overturn the Act.

In a submission to the Senate inquiry, the NLC said it did not support this bill and would only support legislation that preserved the Ngapa clan's existing nomination.

Legislation would also need to enable traditional owners of other lands to facilitate development of their country for a radioactive waste facility if they wished, it said.

"The NLC supports the wishes of traditional owners - whether for or against - regarding uranium related development, or other development, on their country."

But there remains opposition from Aboriginal landowners.

A separate submission from Muckaty Station described the matter as having "an unfortunate, divisive, lengthy history".

"Many members of the small indigenous community at Muckaty have deep concerns over, and are strongly opposed to, the Commonwealth's waste facility," it said.

Mr Henderson was reluctant to comment on the stance taken by the NLC, which offered the site in exchange for $12 million from the Howard Government, saying: "I think this is an issue that needs to be worked through".

"I respect the Northern Land Council's opinion on this but there was an election commitment made by the Australian Government and I expect them to honour that commitment," he said.

The Beyond Nuclear Initiative (BNI) has questioned Labor's commitment.

"The Federal Government is dragging its feet on this very important issue," said BNI spokeswoman Natalie Wasley.

Hearings will continue in Alice Springs on Tuesday.